Lightmaps and Static Batching

Looking at the drawcalls I can see there are some meshes that could be batching together.

Upon further inspecting, I noticed that they have different lightmap indices, which now makes sense why they’re not batching.

Is there a way to tell Unity/Beast to bake lightmap in a way that meshes with same material get the same lightmap index?

I’m using Unity 4.6.6